Sustainable Sites 7.1 – Heat Island Effect – Non Roof

The Heat Island effect occurs when warm temperatures are experienced in urban areas compared to adjacent rural areas because of solar energy retention on constructed surfaces. Basically, all of that black asphalt and concrete on the ground makes areas a lot warmer. This credit reduces this effect.

This credit also mentions the Solar Reflectance Index (SRI). It’s a way to measure a materials ability to reject solar heat. It ranged from 0 (black) to 100 (white). This is not to be confused with emissivity, which is the ratio of the radiation emitted by a surface to the radiation emitted by a black body at the same temperature.

Non-roof

Intention:

Reduce heat islands

Minimize impact on microclimate and habitats

Implementation:

option 1:

provide shade to 50% of site area (within 5 years of occupancy)

provide open grid area (parking, roads, sidewalks) with paving material of SRI 29 or higher.

option 2:

provide 50% parking underground or under roof

provide paving material with SRI 29or higher.

Codes/Standards Applied:

ASTM

Extra Credit:

option 1: provide 100% (instead of 50%) of site shade for 5 year occupany

option 2: provive 100% (instead of 50%) of parking underground or under roof

43 Comments On This Post

Shade is calculated at different times of the day at a particular time of the year, at a certain height. I forget the nos., but it was something like Summer Solstise at 10am,12am,2pm, and 4pm. Please confirm. Thanks!

Valeria, good luck on your exam. I’m glad you’re getting involved with the posts here. You’re doing an awesome job and I know you’ll perform excellently on your exam. Keep up the good work and let us know how you do!

Hi, I am barely starting to study for the NC AP, and I don’t understad what they mean by 50% shade within 5 years of ocupancy. Does this mean that the shading materials should last for 5 years? or I might be over thinking this but, does it mean that if you use trees for shade, you expect the tree to grow into providing 50% shade at a 5 year period???

Has anyone ever questioned the validity of
this credit? How can planting a few trees in front of a 100-storey skyscraper reduce the Urban Heat Island Effect? I would make sense if the trees shaded the top of the building, but we rarely see this in urban settings.

It would make sense for this credit to focus on heat reflective exterior wall coatings with a minimal SR 60 and a TE of 85.

Most buildings within inner cites are tall with small roofs but lots of side walls. A cool roof would shade the top 3-4 floors and cool wall coatings would shade everything else.

This is anecdotal, but when I have used trees in my landscape design, at least in proximity of the building, whether they actually shade the whole roof area or none of it, they create a microclimate under them that definitely lowers the heat island effect..
In San Francisco, the Transamerica bldg has a grove of redwoods and folks hang out and have their lunches there. The rest of the neighborhood is concrete and skyscrapers (financial district)
My house is near 3 redwood trees and the temperature gauge always goes down as I drive into my gravel driveway.
Perhaps that is why they don’t specify that they cover x amount of the roof..

Pat,
Option 1 should read like this:
provide the following for 50% of the site hardscape:
Shade within 5 years
Paving materials having SRI values more than 29
Open grid pavement system at least 50% open
Q=S+P+O. Q is the qualifyng area
Q> T/2 (50%) with T being the sum of all non roof hardscape surfaces.
I think you are saying to provide shade only for 50% of the hardscape area.
Thanks

According to the reference guide, shading within five years, SRI 29+ paving materials, and open grid pavement can all be combined to handle 50% of the hardscape area – not 50% of the site area. Which makes more sense, if you think about it.

Sustainable Sites 7.1 – Heat Island Effect – Non Roof
should Submittal phase for this credit be design phase instead of construction? since the decisions for placing parking under cover should be made during design phase.

You need to look at it from GBC’s perspective. Something can be changed during construction to deny the credit. It doesn’t make that much sense since you can do all the WE credits in design, but that is the way they wrote it.

Question on parking. If you reduce the parking by stacking it, do you count the footprint of the parking that is covered by other parking? ie- 50% is covered since it is under parking- on the other hand, the other 50% which is not covered could be a large portion of the site area, leaving a big heat island. And then if you cover the parking deck which is on top, does that portion of the site area count twice?

Question on Technologies
On the gray 7.1 page with requirements and stretegies they mention vegetated roofs as a strategy for this credit. How can this be, if this is the NON-roof section. Does this credit count as one that should take green roofs into account?

If you want to reduce the heat island effect- and you do so by eliminating hardscape altogether and replacing it with fully permeable landscape rather than semi-permeable paving- do you lose the chance of obtaining this credit?

I am really confused with LEED mumbo jumbo. Sometimes you get “extra credit” for going the extra step (example: 100% shading in SS c7.1), other times you get “exemplary performance” point for doing similar thing (example SS c7.2) and in other cases you get ID credit for doing the same thing. There seems to be no freaking rhyme or reason. My fifth grader can come up with a more logical system.

Hello Azoz and Jobe,
I am a landscape designer and am LEED AP (2007) so my information may have changed, but as far as submitting documentation on any materials to the USGBC, you should collect any verification for any credit.The reason is in the audit, they will choose which credits to ask the required paperwork. In other words, you need to collect all the paperwork as if they would have you submit it all, they choose which ones you need to actually submit.
It is always handy to take a look at the templates on the website as well.

The hardscape issue,Jobe, I haven’t found a gravel company that has tested the SRI value, you might.. but roofing materials are, I might guess those materials matching the colors of the roof would have a similar SRI.

I would be interested if someone does know differently and found a company who has tested decomposed granite for reflectance.

Our company had test performed on a number of exposed aggregate concrete samples with different aggregates so we could decide which aggregates were appropriate. We had samples made and sent to a lab for an ASTM C 1549 report. YOu could do the same for decomposed granite. Whatever the result you would want the contractor to do the same test to make sure the material performs as specified. This is something you would want written into the spec.

BTW does anyone know if “standard” cast in place concrete needs to have an SRI test performed or is reference to the 7.1 table sufficient? There are a lot of variations in concrete color an texture.

Does anyone know if a Photovoltaic Shade Structure Meets the requirements for cover under Option 2? On credit 7.2 PV is basically expmpted along with equipment but for non-roof I don’t know if LEED would accept this in lieu of SRI 29.

Leave a Comment

Please refrain from posting any exam questions that are from the actual LEED exam or other sample exams. This jeopardizes the existence of the open comment format. Such comments will be deleted. Thank you for your understanding.

Find out where LEED exam prep classes are being held in your local area. Training courses will help you get through the exam process quickly and easily.Click for more info....

About Me

Hi! My name is Pat and I’m the guy behind GreenExamAcademy.com. I graduated with a B.A. in Architecture from the University of California Berkeley, and was working in an Architecture firm for the last few years in Southern California...

Get the Newsletter

To get FREE updates and information about LEED v3, please enter your name and email below. I will never give away, trade or sell your email address. I HATE SPAM, and you can unsubscribe at anytime.

Hey i cleared yesterday with a score of 185.. i started studyin one month back and followed this website thoroughly.. thanks a lot pat for creating this website.. i followed the same study schedule as yours..